Improved power tool guard.

Abstract: A guard (12) for mounting on a power tool (1), which guard is of one piece construction, and comprises a central transparent region (14) surrounded by an outer non-transparent region (16) and is adapted for mounting on the power tool (1). The guard is particularly suitable for mounting on a hedge trimmer or chain saw.

Description: The present invention relates to a guard for a power tool, in particular a guard for a hedge clipper or a chain saw. It is know to provide guards for power tools of this type, in order to protect the operator of the tool from flying debris generated during the operation of the tool. The first guards provided were manufactured from non-transparent material and, while they provide acceptable protection for the operator, they have the disadvantage that a substantial part of the working area is obscured from the operator. In an alternative known design, the guard is made from transparent material. While this overcomes the disadvantage of obscuring part of the working area, it does have the disadvantage that the operator can see not only the working area but the surrounding parts of the tool body. In a further alternative design, the guard has been manufactured from non-transparent material, but the central region has been made of mesh. This has the disadvantages that it is expensive to manufacture, because of high tooling costs, and the protection for the operator is reduced by the fact that fine debris, such as small twigs and other similar material, can pass through the holes in the mesh. It is an object of the present invention to provide a guard for a power tool in which the above disadvantages are reduced or substantially obviated. The present invention provides a guard for mounting on a power tool, which guard is of one piece construction and comprises a central transparent region surrounded by an outer non-transparent region, and is adapted for mounting on the power tool. The guard according to the invention is of one-piece construction, which is advantageous for cost and strength; avoids the possibility of the transparent portion falling out, and provides maximum clarity. The guard according to the invention is preferably manufactured from synthetic plastics material, and suitable materials include polycarbonate, styrene-acrylo-nitrile (SAN), polypropylene; acrylonitrile-butadiene-styrene (ABS) and styrene. The guard according to the invention is preferably manufactured by a moulding process, in particular injection moulding. The non-transparent portion is made non-transparent by texturing the surface on both sides in the mould, suitably by spark erosion or chemical deposition. It is a requirement of the moulding process that the areas of the mould which correspond to the central transparent region have highly polished surfaces. An embodiment of a guard according to the invention will now be described with reference to the accompanying drawing, which is a perspective view of a hedge trimmer on which an embodiment of a guard according to the invention is mounted. The hedge clipper (1) comprises a housing (2) in which are mounted a switch trigger (4) and secondary handle (6). Cutting blades (8) extend from the housing (2) and are provided with a cover (10) for use when the hedge clipper is not in operation. A guard (12) is mounted on the hedge clipper (1) and comprises a central transparent region (14) surrounded by a non-transparent frame region (16). In use, the operator activates the blades (8) of the hedge clipper (1) by means of the switch (4) and is able to observe the cutting action of the blades (8) through the transparent region (14) of the guard (12).

Claims: A guard (12) for mounting on a power tool (1), characterised in that the guard (12) is of one piece construction, and comprises a central transparent region (14) surrounded by an outer non-transparent region (16) and is adapted for mounting on the power tool (1). A guard according to claim 1 characterised in that it is manufactured from synthetic plastics material. A guard according to claim 2 characterised in that the synthetic plastics material is polycarbonate; styrene-acrylo-nitrile (SAN); polypropylene; acrylonitrile-butadiene-Styrene (ABS) or styrene. A guard according to claim 2 or claim 3 characterised in that it is manufactured by a moulding process. A guard according to claim 4 characterised in that the non-transparent region (16) is manufactured in the mould by spark erosion or chemical deposition. A power tool characterised in that a guard according to any of claims 1 to 6 is mounted on the tool.

Inventors: STONES KEVIN, STONES, KEVIN
Applicants: BLACK & DECKER INC, BLACK & DECKER INC.
Application year: 1994
Main classification: B27B17
IPC codes: A01G3, F16P1, B27G19